1. Field of the Invention
The present invention relates to a sunlight blocking device, and, in particular, to sunlight blocking devices which establish a thermal control mechanism for a spacecraft having a directionally controlled main body, i.e. one situated in an orbit having a low angle between the orbit plane and the sun vector, such as a low inclination orbit, and generally, an equatorial orbit. Spacecraft as used herein includes satellites and other space bound vehicles.
2. Information Disclosure Statement
The following patents are generally representative of the prior art in the broad field of solar cells sun shields for various types of spacecraft:
U.S. Pat. No. 4,133,502 to Andrew Anchutin describes a plurality of arrays of solar cells which are symmetrically stored about a spacecraft during launch to provide symmetrical loading. When the spacecraft is in operational configuration, the solar arrays are deployed adjacent each other on one side of the spacecraft to effectively form a single array and the single array may be oriented to face the sun by a common drive mechanism.
U.S. Pat. No. 4,508,297 to Guy G. Mouilhayrat et al, describes an equatorial orbit satellite with solar panels having blades with a median line inclined at a certain angle relative to the equatorial plane. Thus, the field of vision of the antennas is free and disturbing torques become acceptable.
U.S. Pat. No. 4,725,023 to Haruo Shiki describes a geostatic satellite which comprises a spinning drum for stabilization which spins around an axis of rotation which is parallel to the axis of the earth. A paddle member loaded with solar cells is directly rotatable about the same axis and is controlled such that the solar cells face the sun. A despun platform supports communication gear and maintains the gear pointed to a relatively fixed point on earth. A shading device for shading the electronics laden despun platform from the sun, is attached to the paddle member and rotatable therewith. Thereby, the shading device will always be disposed between the sun and the despun platform.
U.S. Pat. No. 5,372,183 to Harold P. Strickberger describes a spacecraft adapted for operation in a low inclination angle earth orbit which comprises north, south, east and west panels defining a spacecraft interior volume. The north and south panels are oppositely disposed with respect to each other and the east and west panels are oppositely disposed with respect to each other. The spacecraft interior volume generally and preferably lacks structural elements that substantially restrict thermal radiation among the panels. The north and south panels, to which spacecraft equipment is usually mounted, each include conductive heat pipes for reducing the temperature difference across each panel. The exterior surfaces of the north, south, east and west panels have a covering, preferably of optic solar reflectors (OSRs), for radiating thermal energy therefrom, wherein the OSRs have a solar absorptivity that is substantially less than their thermal emissivity. The interior surfaces of the north, south, east and west panels have a covering for effectively radiating thermal energy between and among the panels across the interior volume.
Notwithstanding the prior art, the present invention is neither taught nor rendered obvious thereby.